The disclosed embodiments relate to the field of determining the quality of a mobile telephony service, and in particular to the field of determining the quality of a mobile telephony network from the point of view of a user.
A mobile telephony network enables a mobile station, normally a telephone, to develop in a covered space bounded by the radio section of the network. This radio network, called BSS (Base Station Subsystem), consists of a hub of base stations, called BTSs (Base Transceiver Systems) for GSM or Node B for UMTS, and of their control stations, called BSC's (Base Station Controllers) for GSM or RNC for UMTS. The routing section of the network, called NSS (Network Subsystem), has the task of routing the call between two users of the network or outside the network, such as a fixed network, for example. This section consists of several MSCs (Mobile Switching Centres) which route the calls. The list of clients of the network operator is managed at this level by a single database, the HLR (Home Location Register). Correct operation of the different elements of the network is ensured by the operating and maintenance section of the network, also called OSS (Operation Subsystem).
Despite the maintenance carried out by the OSS it sometimes happens that users experience problems in connecting to the network from their telephone. These problems may be due to a connection difficulty, a communication problem or a sudden interruption in the communication. It may happen that these connection difficulties pass unnoticed in terms of the technical indicators for network quality. In fact, the technical indicators only allow a partial indication of the network status because these cuts or deteriorations may be due to technical problems arising at certain points of the network without technical indicators. Similarly, certain problems detected by the technical indicators are not apparent to the client because the network has recovered. Although the information provided by the technical indicators of the network relates to technical incidents on the network that may affect the client, it may also relate to incidents that have no effect.
To counter this problem several solutions have been established. On the one hand sensors, called “layers”, which consist of automatic call generators, have been installed, and on the other testers are used to pass through the network testing its quality. Nevertheless, these solutions are considered very expensive and only supply information at particular points on the network at a given time, without enabling an overall representation of the network to be obtained that can be accessed by the user. Moreover, the analyses of the cuts known as “manufacturer equipment source” cuts are not comparable between equipment suppliers and are not representative of all the cuts encountered by the network users.